VCCA Home Forums GENERAL DISCUSSION General Discussions yr 54 235 3 speed exhaust tail pipe OD size question

need to replace the exhaust system pipe (from the muffler back),..on our 54 - 210 - 2 door post - car project. Suppose I'll take the old stuff down to the corner muffler shop and get something in aluminized steel bent to match. The car looks to have the original 2" exhaust down pipe (up front of the muffler), it still had enough meat left in it to allow me to clean it up and repaint with high temp..

Question please:

The exhaust pipe that was on this car, (from the muffler back) was all 1-3/4" OD pipe. It also was not bent on a mandrel so the bends further reduced the size of the pipe in bend areas.. I don't have a lift, so the car is sitting on jack stands, therefore I had to cut off a couple feet of the rear most straight tail pipe section to get it all past the third member and out from under the car. Initially I figured I'd just go back with the same thing (1 3/4" OD pipe at the rear) just to make things simpler, cheaper, and easier to get back in place...however, after spending a little time re-searching here on the computer, that may not be the right thing to do. I found the following muffler port in/out info listed on another forum web site, as follows:

chevy yr 41-49,.... 2" OD exhaust manifold flange, 1 - 11/16 " OD tailpipe flange
chevy yr 50-55,.... 2" OD exhaust manifold flange, 1 - 51/64 " OD tailpipe flange

If this information above is correct, (and the tailpipe OD was enlarged slightly to accommodate the extra HP for the 235/powerglide....(1 - 51/64's is 3/64 " larger than 1 3/4" )..which is awful close... ??

There also are a couple of charts currently present on the internet that show exhaust pipe sizing for engines of all sizes. The charts are laid out showing engine CID, HP max, CFM, and pipe OD size for both single and dual exhaust systems. According to these charts, anything smaller than 2 inch (single exhaust), is too small for the 235 engine - with the 2 inch pipe being adequate on some charts and not quite enough on other charts...

Any body out there had any experience using a 1 - 3/4 inch exhaust pipe, from the muffler back ? Anyone else out there removed 1- 3/4 pipe from the rear of their exhaust system and replaced with 2 inch ? Any difference ? etc...

2" is fine with me, but again (even though it's just a 1/4 inch larger OD) it still sticks in my mind that using the same diameter as what came off should make for an smoother replacement.. all that said, I'd never want to repeat someone's previous mistake, just to make things easier.....if it needs to be 2" OD minimum - we'll make it fit,..if it can be 1 3/4" and the car will never know the difference,...even better..

Hopefully some of you old time Chevy guys will see this and speak out. Your knowledge is priceless and very much appreciated.

Steve

The 1950-1952 235 engine with Power Glide cars has a 1 3/4" tail pipe.(except convertible)
The 1953 passenger car pipe was also 1 3/4" and works perfectly well on a 1950. 1954 pipe is shorter as the muffler is longer.

a slightly smaller pipe such as the bent pipes will not reduce engine performance under 80 MPH.

I agree with Gene, unless you are race tuning and racing the 235 the 1 3/4 pipe will make no appreciable difference to the performance at normal driving conditions. My guess is that most show judges would not notice the smaller pipe.
Tony

What size is the outlet of your muffler ? The tailpipe should snugly slip over that. If too large you will have problem getting it so it won't leak.

Dick

I have the 1 3/4" on my 1950 my P.G. , slips over the muffler outlet, looks orignal (had the tip flattened like original) and car will do 90 MPH.

Thank you Gene, Tony and Dick,...for the reply's back on this.. I really appreciate it. I'm not a racer at all, I just don't wanna unknowlingly undersize and cause things to labor un-necessarily.

I believe Dick mentioned the "tail pipe should slide over the muffler outlet" - that is not the case on this exhaust, and it brings up a good point for clarification that I should have included in my original post. My muffler has a 2" ID inlet and outlets .

That said, the 1 3/4 " pipe I'm questioning, that was on this car, at the rear,...was 1 3/4 " OD exhaust pipe and whomever had replaced the muffler and used a small piece of 1 7/8" od pipe as a steel downsizer ring that the 1 3/4" od rear Tailpipe then slid into.

Gene when you replied back "that you had 1 3/4 pipe that slipped over your muffler outlet" we're you speaking of 1 3/4 " OD pipe or 1 7/8 " OD exhaust pipe with a 1 3/4" ID ?

thanks again guys - I'll be anxious to see your reply's back as this really helps me.

Steve

Dick the muffler on this car is not anything near stock, but I did really like the sound of it,...it's just a simple 24" long red glass pack style muffler with a 2" ID inlet and outlet.

Steve

great info Gene, I appreciate it...just so I'm clear here on my end on this, when you say 1 3/4", we're both talking about 1 3/4 " OD pipe ? correct ?

thanks again

Steve